The appearance of streaks that distort 2-D electrophoresis maps is a common problem, occurring most frequently when running gels that contain regions greater than pH 7.0. Increased sample load, increased length of the IPG strip, or using a narrower pH gradient worsen the problem. Extra spots on 2-D gels, caused by nonspecific oxidation of proteins, is another difficulty encountered when running gels containing basic regions. Both streaking and nonspecific oxidation result in poorly resolved protein patterns and reduced reproducibility between electrophoresis runs. DeStreak Rehydration Solution effectively eliminates nonspecific oxidation by maintaining protein thiol groups in a single oxidation state, irrespective of sample load, pH range, or run length. Protein patterns are stabilized in IPG strips of any length and pH gradient ensuring the same stable and reproducible pattern in every analysis. The effectiveness of DeStreak Rehydration Solution is maintained at the high sample loads and long run times required for preparative gel electrophoresis.